Keyboard lock



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ra L fr@ f u 0 3 6 1C//v 1% 1%/ .w H ma m. u vw mm M f m ATTOR N EY Patented July 1,1, 1933 UNITED lSTATES PATENT OFFICE ELMER kGr. ELLIOTT, OF LOS ANGELES, CALIFORNIA, ASSIGNOR TO WILLIAM 1T. PEARSON,

' OF LOS ANGELES, CALIFORNIA KEYBOARD LOCK Application filed October 23, 1931. Serial No. 570,624.

This invention relates to improvements in key board locks for parcel post machines and the like, such as is disclosed in a copending application Serial No. 367,106, titled Parcel kpost weighing `and stamp printing machine,

filed May 29, 1929, by William. J. Pearson; designed for weighing parcel post packages and the like and for printing metered prepaid-stamps for the same.

More particularly my invention relates to the key board portion of such a machine and the controlling` elements incorporated therein.- My invention relates to the locking of two of these elements, wherein when one is operated the other is automatically locked against operation until the first one is released, to prevent interference between the operating elements of the machine.

An object of my invention is to provide a key board containing a plurality of nonsimultaneously operable keys, for example: a control key, for operating a power unit Within the machine, and, an error key by means of which combinations of figures which have l been set up in the machine may be cleared at the will of the operator; and means whereby wheneither of said keys, for example the error or the control key, is depressed by the operator the other key is locked against depression until the first key is released.

Another object of my invention is to providey a control for a parcel post machine whereby the operation is so simplified that an operator may operate the machine without interference between the control and the error key, by having the one that is depressed lock the other key against depression.

Another object of my invention is to provide a locking mechanism of simple character that will automatically lock one key by the operation of the other and thereby provide a more simple and efficient method of operation ofthe machine.

To the above and other objects my invention consists of the novel construction, arrangement and combina-tion of parts as hereinafter fully, clearly and concisely described and definitely pointed out in my claims and illustrated by the accompanying drawing, in

which Fig. 1 is a front elevation of a portion of a parcel post machine key board showing a pair of non-simultaneously operable keys for example the error and control keys of said machine. 'l

Fig. 2 is an elevation in section taken from the left on line 2-2 in Fig. 1, showing the keys and the lock in normal rest position.

Fig. 3 is an elevation in section taken from the left, similar to Fig. 2, showing the error key depressed.

Fig. 4 is an elevation in section from the left, similar to Figs. 2 and 3, showing the control key depressed and the error key locked.

Referring to Fig. 1, a section of a key board plate is shown with a plurality of keys, which in the illustrative embodiment of my invention described herein may be referred to as, control key 11 and error key 12 and a third key 13 which may be one of the remaining keys of a key board. The key board plate 10 is supported on frame 14, in which are rotatably mounted rock shaft 15, and lock shaft 16, and on one end of shaft 16 is mounted the latch 17, which is designed to engage with the detent 18 in the-error key bar 19.

Referring to Fig. 2, the error key bar 19 is seen to be pivoted at 20 to clutch trip 21. which is mounted on shaft 15 and tensioned by spring 22; the control key 11 is mounted on key bar 23, to which is connected, at 2&1, bell-crank 25 mounted on shaft 26, and which in turn is connected at 27 to power clutch lever 28 which it operates.

Control key bar 23 has connected to it link 29, which in turn is connected to a portion 30 of the latch 17 made in the form of a lever and rockably mounted on shaft 16, and through which, when the control key 11 is depressed, the latch 17 is thrown into the path of the detent 18, thus locking the error key 12.

Referring to Fig. 3, the error key 12 is shown in depressed position where it has depressed the clutch lever 21 and presents to the latch 17 the face of the key bar 19 at a point 31; should the control key 11 be depressed, while the error key is in the position shown, the latch 17 would contact the said bar face 31 and be restrained against further action, thus locking control key 11 against complete depression. The lever 28 is provided with tension spring 82 having one end attached thereto and the other end attached to the casing 33 for the purpose of returning the key 11 to original position after depression.

Fig. 4 .shows the control key 11 in depressed position, with the error key 12 in normal position; the related parts have been operated to lock the error key 12 against depression by the latch 17 having been thrown into the path of the detent 18 thus preventing depression of the error key bar 19.

It has been found in the loperation of par- Cel post machines, provided with a key board for setting up combinations of numerical figures in the printing portions thereof and combinations within a meter actuating mechanism associated therewith, that a control key, herein designated as the error key 12 designed to be used to clear the machine of andy combinations set up therein, may be acc1 entally depressed by the operator of the e machine during his manipulation of the key board and more particularly when operating the control key 11'to cause the machine to print the numerals set up therein and register within the meters the set-up combinations; therefore, I have provided a means of preventing accidental clearing of the machine, through the error key, when operating the control key, by the automatic lock herein disclosed.

In operating the machine, when the operator depresses the error key 12, the control key 11 is automatically locked against depression, and consequently there can be no printing operation of' the machine, While it is being cleared, to print an incomplete postage stamp, or register in the meters therein an amount not printed on a postage stamp.

'F or a full description of all the remaining portions of the parcel post meter device in combination with the key board lock herein described, reference is made to the United States patent application offGeorge 1V. Lawrence, for Automatic keyboard, Serial No. 57 0,622 iiled October 23, 1931.

While the form of mechanism here shown and described is admirably adapted to fulfill the objects primarily stated, it is to be understood that it is not intended to confine the invention to the one form of embodiment herein disclosed, for it is susceptible of embodiment in various forms, all coming within the scope of the claims which follow.

Iclaim:

1. In a device of the character described, a keyboard having keys mounted thereon, key bars extending from said keys, and a detent connected by a flexible connection to one key bar and movable therewith to intercept a second key bar when the first mentioned key is depressed, the free end of said detent being positioned to engage the face of said second key bar to prevent operation of the first-mentioned key bar when the second key is depressed.

2. A keyboard lock comprising a plurality of keys having key bars, a pivoted detent, a link connection between said detent and one of said key bars, and a second key bar having a projection on its face, the free end of said detent normally bearing upon the face of said second key bar and through its link cnnnection restraining operation of the firstmentioned key when said second key bar is depressed, said detent also engaging said projection to prevent operation of the second key when the iirst key bar is depressed.

3. In a device of the character described, a keyboard having keys thereon, a frame supporting said keyboard, key bars extending from said keys, a detent, a pivotal support carried by said frame, said detent mounted at one end on said pivotal support, a link connection between said pivotal support and one of said key bars, a second key bar having a projection thereon, the free endof said detent engaging said second key bar to prevent operation of the iirst key when the second key is depressed, and said detent moving with said iirst key bar to bring the free end of the detent into latching engagement with said projection to prevent operation of said second key when said first key is depressed.

In testimony whereof, I have hereunto set my hand at Los Angeles, California, this 17th day of October,'1931.

ELMER G. ELLIOTT. 

